Stereochemistry and Near-Infrared Circular Dichroism of a Chiral Yb Complex

摘要: The near-infrared CD spectrum of ytterbium complexed by DOTMA, [DOTMA = (1R,4R,7R, 10R)-α,α‘,α‘ ‘,α‘ ‘‘-tetramethyl-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid)] is presented. This the first report a in solution f−f transitions complex whose structure and dynamics are completely defined. shows several well-resolved around 980 nm with very high dissymmetry factors. In water methanol, there two diastereomeric conformations YbDOTMA equilibrium, Λ(δδδδ) or n Λ(λλλλ) p, being latter always large excess. relative proportion depends on temperature solvent composition, but rather insensitive to these parameters, which demonstrates that neglecting minor form contribution an acceptable approximation. On lowering temperature, presence hot bands highlighted, leads tentative assignment transitions. absorption count...